2 x 1ghz processor vs 1 x 2ghz processor?

what is faster? 2 physical 1ghz, say, underclocked pentium 4's or 1 physical 2ghz pentium 4? same processor... just different clocks.
how about a dual core pentium 4 (i kno it doesnt exsist) at 1ghz vs 2 physical 1ghz pentium 4's...
some website write..
2.66 x 2 Core 2 Duo processor... just wondering if that is wrong.\
thanks in advance!

 

2.66 x 2 core 2 duo:
They are just trying to tell you it has two cores. Not that there are two core 2 duo processors.

1 CPU @ 2ghz is faster than 2 CPUs at 1ghz each.

 

And there was a dual-core Pentium 4 - it was called the Pentium D.

 

Is there even such a thing as a dual-processor Core 2 system? Or did Intel purposely introduce some sort of technical barrier to force people to use Xeons, like they did with the Bloomfield i7's?

 

You mean two physical processors, where each processor has two cores? That is exactly what a Xeon processor is...it is a Core 2 Duo (or more recently an i7) that has additional hardware necessary to allow two physical processors to communicate with each other.

 

Yeah, but Xeons are not only much more expensive than their equivalent consumer counterparts, they also require other expensive hardware like FB-DIMMs. It's not like you can just pair a two socket mobo and 2 Xeons with other standard PC hardware.

 

I know. But the point is that Xeons have the additional hardware needed to use two processors in one system. Those processors are usually targeted towards corporate environments thus a few other features like FB-DIMMs are standard, where things that like are actually useful.

Not to mention lower demand for that kind of system mandates higher prices.

I almost build a single processor Xeon system (with intention to move to dual Xeon in the future) but decided not to for a few reasons.

 

Ghz is meaningless today unless we are talking about same CPU series: P4 vs P4, Core2Due Vs Core2Duo, i7 vs i7. Other than that the only way to tell which is better is benchmarking.

 

The newer Xeons are built on the i7 architecture, as are the latest processors from Intel. The previous generation of Xeons similarly used the same architecture found in the Core 2 lineup. Very fair to compare them....they are technically the same CPU family.

 

Err, did somebody at any point in this thread compare Ghz across different architectures?

 

Well, his point is very true...but not relevant to the current discussion.

 

i totally agree.. people these days... they miss the point.
i know that there is no dual cpu setup of a c2d..
in a video about macs it said that a dual 500mhz processor was like a 2ghz p3 if it exsisted, while a 500mhz alone was compareable to a 1ghz p3.

 

http://www.youtube.com/watch?v=mIIs-KyNgc4

 

And what Processor is Apple using now??!!
Talk about hypocrisy.
Mac Fans always fail to remember the inconsistency in their Apple Speeches.
Anyway the only thing Apple is good at is trashing competitor's products in public advertising without much truth.

 

Indeed, that video makes Steve Jobs look like a fool. Then again, the whole Apple message is full of contradictions anyway so this is nothing special.

 

And not all xeon processors requires fb-dimm. Some use standard ddr-2 ram as well and they're sometimes cheaper or about the same price as their equivelent core2duo.

 

Yes, but not i7 to Core2Duo for example.

The title of this thread might have put some in erroneous path.

 

1 x 2GHz, aka single 2GHz processor is ALWAYS faster than a 2 x 1GHz processor. If the 2 cores aren't bound by things like interconnect latency/bandwidth, cache conflicts, memory, you'll definitely be bound by having much less apps optimized well for the 2 cores.

 

When i say 1x2 i mean 2 physical cpu's

 

Assuming we are talking about the same architecture throughout, 2 x 1 GHz processors like in a dual core CPU should work faster than a single core 2 GHz processor because there is less time lost in the process of switching programs. It's like a 2 lane high way with a 30 mph speed limit and a single lane highway with a 60 mph speed limit. Plus if a "lane" gets blocked or bogged down, there is still one lane open and moving even if it is "slower". I remember moving from a 2.6 GHz Athlon 64 Mobile 4000+ to a Turion TL-56 x2 1.8 GHz. They are both similar architecture, accept the Turion having essentially two Athlon K8 cores with half the cache each of the Athlon 64 4000. You know what? If you do something as silly as just adding up the clock speeds of the Turion x2 (3.9 GHz) and comparing it to the 2.6 GHz of the Athlon 64 4000, you'd still be pretty far off as far as the comparable performance gain is of the Turion x2. While the GHz comparison says the Turion should be 50% faster, it's more like 75% thanks to less program switching and being able to process two programs at a time. Parallelism is certainly a nice perk of multi-core processors. My experience with the Turion x2 1.8 GHz felt like more than just 75% increase of the performance of the Athlon 64 4000, it was much more like double if not more. Multitasking is much easier and more stable.

Now if we come to the issue of two physical CPUs, then you are running into interconnect issues as said by a poster a couple posts before hand. This was a huge issue with the "Quad FX" (I think that was the name) platform that AMD released as a stop gap measure to make it possible for AMD lovers to have 4 CPUs (by having 2 dual core cpus) in a single system before the first Phenoms came out. The 2x performance wasn't there like hoped to compete with the then-cutting edge Q6xxx Intel quad cores. Quad FX was just a dud.

 

Which is technically the same thing. With 2 physical CPUs, its even worse off.